MOLECULAR CHARACTERIZATION OF ESBL-PRODUCING ESCHERICHIA COLI ISOLATED FROM HEALTHY CATTLE AND SHEEP

The present study aims to characterize ESBL-producing Escherichia coli isolated from healthy cattle and sheep in the Burdur province of Turkey. Fecal samples from a total of 200 cattle and 200 sheep were tested and ESBL-producing E. coli was isolated from 31 (15.5%) cattle and three (1.5%) sheep samples using the Clinical and Laboratory Standards Institute's combined disk method. Among the ESBL gene classes detected by PCR, bla(CTX-M) was the most frequent type, followed by the bla(TEM) and bla(SHV) families. ESBL-producing E. coli isolates showed co-resistance to multiple classes of antibiotics including aminoglycosides, phenicols, quinolones, folate pathway inhibitors and tetracyclines. The resistance rates were higher in the cattle isolates than in the sheep isolates. Phylogenetic grouping of the E. coli isolates indicated group A (particularly A(1)) was the predominant phylogenetic group (19/34, 55.9%), followed by groups B1 (9/34, 26.5%) and D (6/34, 17.6%); none of the isolates belonged to group B2. The study shows that ESBL-producing E. coli isolates exist in the intestinal flora of healthy cattle and sheep in the Burdur province of Turkey. This is the first report showing the emergence of CTX-M type ESBL-producing E. coli in sheep farms in Turkey.